Cerebral swelling after normothermic cardiopulmonary bypass.
BACKGROUND
Marked cerebral swelling visible on magnetic resonance images has been found immediately after hypothermic (28 degrees C) cardiopulmonary bypass. The mechanism is unknown, but indices of cerebral ischemia are seen during rewarming from hypothermic bypass that are not present with normothermic bypass (37 degrees C).


METHODS
T1-weighted and fluid-attenuated inversion recovery magnetic resonance images were taken of seven patients undergoing routine coronary artery bypass surgery before, 1 h, and 7 days after the operation using normothermic bypass.


RESULTS
Marked cerebral swelling was seen in fluid-attenuated inversion recovery images in five of seven patients 1 h after bypass. Scans in four patients taken 7 days after bypass showed that the cerebral swelling had returned to normal. There was no change in cerebral ventricular size, and all patients had uncomplicated postoperative courses.


CONCLUSIONS
Normothermic bypass is followed by acute postoperative cerebral swelling. However, the amount of swelling was similar to that found in a previous study after hypothermic bypass. The mechanism of swelling is still obscure, and its relation to neurologic outcome is unknown.
Harris
D N
DN
Robert Steiner Magnetic Resonance Unit, Imperial College School of Medicine, London, United Kingdom. dharris@rpms.ac.uk
Oatridge
A
A
Dob
D
D
Smith
P L
PL
Taylor
K M
KM
Bydder
G M
GM
D000368:Aged; D001929:Brain Edema / Q000175:diagnosis / Q000209:etiology*; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D006801:Humans; D007036:Hypothermia, Induced; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D011183:Postoperative Complications